In a move that will astonish both critics and supporters, David Cameron has appointed the controversial Happy Mondays star Shaun Ryder as a special adviser on social class, following a series of political missteps since the budget.

The decision is believed to have been taken after urgent discussions between the so-called Quad group of ministers, comprising Cameron, George Osborne, Nick Clegg and Danny Alexander, the chief secretary to the treasury.

The group feared that budget decisions to lower the 50p tax rate and raise VAT on hot takeaway food were in danger of retoxifying the Tories as a "party of the rich". "It's been a terrible week and a half, and the thinking was that a bit of working-class nous and glamour would be very welcome," said a source close to Downing Street. "Discreet inquiries established that Ryder was not the committed Labour supporter that people might think he is."

Ryder, the lead singer of the re-formed Happy Mondays, was a popular runner-up in ITV's I'm a Celebrity … Get Me Out Of Here in 2010.

Spin doctors believe that his credibility and authenticity could rub off on a government that has increasingly lost the common touch. He will advise on presentation of all coalition policies that affect the least well-off. He has already devised a T-shirt which makes light of "pastygate", adapting the George Osborne mantra "We're all in this together".

Denise Van Outen in the campaign T-shirt. See the other celebrities
here. Photograph: With apologies to Sport Relief 2012

Celebrities including Claudia Winkelman, David Walliams, David Tennant and Miranda Hart have agreed to model the T-shirts, which picture Cameron eating a pasty alongside the slogan "We're All Eating This Together" and look set to become cult items.

Ryder said that he was taken aback when he received the phone call from No 10. "I never thought I'd see the day when the prime minister was ringing me for advice," he said. "But let's face it, after the past week or so, with pastygate and everything, they obviously need help.

"People assume I'm a lefty because I'm working class and from Salford, but I'm not really. The Mondays were all children of Thatcher's generation. The hefty wedge they offered helped as well. It's funny because it seems like everyone else is paying for an invite to No 10 these days, and I'm the only one who is getting paid to go there, which is nice."

The former hellraiser gave up the wild lifestyle a few years ago and is now a changed man. His autobiography Twisting My Melon was a bestseller, and tickets to the Happy Mondays gigs are selling out. He credits going into the jungle on I'm A Celebrity … with helping to change the public perception of him, and thinks it could do the same for Cameron.

"They've never had a prime minister in the jungle, and I'm not sure how he could fit it around the day job, but it could allow people to see him in a new light: I'm a prime minister, get me out of here!"

Ryder, once banned from appearing live on Channel 4, is now a regular guest on daytime TV shows such as This Morning. "One of my favourite shows is Celebrity Juice, so I'm going to suggest to Dave he goes on there. He needs to show he's not too stuck up. People think Dave laughs at the working class. He needs to show he can have a laugh at himself."

Ryder aims to put an end to pastygate by bringing Cameron to a proper northern chippy in Salford. "My mam and dad ran a chippy, so I know what I'm talking about. Dave needs to be seen tucking into chips and gravy. Everyone knows you can't get decent gravy down south, so that will get him brownie points in the north."

The singer and his manager Warren Askew will also invite Cameron to the Mondays' gigs. "Maybe I'll take him to see the Stone Roses as well, so he'll show he's down with the man on the street."

Ryder also hopes this is the beginning of a special relationship that works both ways. "I want to run for mayor of Salford, so I'm hoping my new mate Dave can help me out."

Political stars

■ Brian Eno's long-term support for the Lib Dems was rewarded in 2007 when the 61-year-old became Nick Clegg's official youth adviser.

■ Last year London mayor Boris Johnson sought to use his celebrity contacts when he teamed up with pop-star – and former husband of best-selling author Katie Price – Peter Andre to launch a new literacy drive.

■ Already touted by some as a possible mayoral candidate for Labour, celebrity businessman Alan Sugar became Lord Sugar in 2009 when he took up the role of then prime minister Gordon Brown's 'Enterprise Champion'.

Shaun Ryder of the Happy Mondays has been appointed a special advisor on social class by David Cameron. Ryder's first initiative was to launch this T-shirt campaign with the help of his celebrity friends